About 222,500 new cases of lung cancer were diagnosed in the United States in 2010. Lung cancer accounted for about 28% of all cancer death in 2010 and it is the number one cause of death among all cancer types (Cancer Facts & Figures 2010 American Cancer Society). The five-year survival rate, standing at 17% (2002-2005), has improved very little in the past three decades.
Early diagnosis of lung cancer is difficult. For those with advanced stage lung cancer, chemotherapy has been the main-stay of treatment. But response is only modest and the median survival short, ranging from 8 to 13 months in clinical studies. In contrast, with best supportive care (without chemotherapy), survival is about 4-6 months. However, the true average survival may be less than the published data, as clinical trials typically enroll younger and medically fit patients, or in other words, an enriched population. It is also well known that the conventional chemotherapies can cause significant side effects and decrease quality of life.
In the past five years, two subsets of lung cancer patients have been identified for targeted therapy: 1) those who harbor an Epidermal Growth Factor Receptor (EGFR) mutation can be treated with Erlotinib, with a progression free survival of up to 9 months reported, and 2) those with ELM-4-ALK gene mutation can be effectively treated by Crizotinib. The challenge facing lung cancer doctors is that outside these 2 subsets, the majority of lung cancer patients, estimated to be 80-85% of the lung cancer population, have multiple mutated genes, and hence, multiple activated pathways. Therefore, the aforementioned targeted therapies have no or minimal therapeutic effects for them.
A recent French study looking specifically at stage IV elderly (age>70) lung cancer patients treated with either combination or single agent chemotherapy suggests that the elderly do benefit from aggressive treatment but they also experience more severe treatment related side effects. In the meanwhile, the cost of care for cancer patients has escalated quickly with the advent of new technology and very expensive targeted agents. Cost of cancer care now accounts for 5% of the total Medicare expenditure. There is a huge unmet need for safer, milder and more cost effective alternative treatment for advanced lung cancer.
Chinese herbal medicine, based on entirely different theory and practice, has helped patients with various diseases over the past thousands of years. Many cancer patients have sought Chinese herbal medicine for relief from the side effects of chemotherapy and radiation or to strengthen and balance their immune systems, in order to live better and longer.
Scientists in pharmaceuticals and biotechnology fields have studied different herbs for their anti-tumor activities and there is now abundant evidence that many herbs do have in-vivo and in-vitro anti-tumor effects.
As many of the currently available chemotherapy drugs come from natural products, and plants have been the basis of almost every new class of medication, it makes sense that plants can act as anticancer agents. Every herb has its own character, but only in combination will herbs have outstanding effects. Scientists often attempt to isolate one particular molecule or compound from the herbal composition, but in the Chinese herbal theory, the anticancer activity is due to the synergy between many of the compounds contained in the extract.